Numerous plant extracts and pharmaceuticals have been identified as promoting overall hair follicle health and even promoting hair retention during a follicle rest period. Unfortunately, some users of such products are dissatisfied by the results obtained with such conventional products. Dissatisfaction may occur even in instances when the formulation achieves good results in vitro as well as under controlled clinical studies.
There has been considerable research effort expended to understand the biochemistry of hair retention and to develop compounds promoting hair retention. Unfortunately, there have not been commensurate advances in the development of delivery systems for the transport of topically administered compounds into contact with target cells within the hair follicle in general, and in particular, to the follicle basal cells.
The anatomy of the hair follicle includes the outermost layer of corneum stratum that has dead and dying dermal cells that form a constriction around the protruding hair shaft. Sebaceous secretions also coat the hair shaft and render the path a topical hair retention agent must take to reach the follicle physically blocked and hydrophobic. Prior art attempts to administer active agents to the follicle basal cells using emulsions have met with limited success owing to the user displeasure with the application of this type of vehicle to the scalp. In addition, emulsions are known to change topical delivery kinetics of active agents (S. Y. E. Hou et al. “Phase volume and partitioning effects on drug delivery from topical emulsions”; International Journal of Pharmaceutics, 66 (1990) 79-85).
Thus, there exists a need for an exfoliating, hair retention-promoting formulation to more efficiently deliver hair retention-promoting agents to the hair follicle. There also exists a need for such a formulation that is an aqueous solution or suspension.